The team was made up of U.N. observers, members of the Revolutionary Armed Forces of Colombia, FARC, and police officers.

The team was attacked while working in Caloto, a remote municipality in the south of Colombia, to remove explosives that had been left in hiding places during the armed conflict between the FARC and the Colombian government.

“During the attack, a member of the Peace Unit Unipep was injured. The rest of the group who were part of the operation were unharmed and are safe,” stated a press release from the U.N. mission.

The National Liberation Army, ELN, has refuted allegations they were involved in the attack

“The ELN denies responsibility for the attack on the U.N.Mission to Colombia,” the group said in a message on Twitter.

After the FARC completed the weapons handover in June, the U.N. Mission in Colombia has worked to extract weapons and explosives located in 779 hiding spots with the help of FARC members and the police force.

The attack on the U.N. mission comes amid escalating number of murders against social leaders in Colombia.Nearly 200 social leaders have been murdered in Colombia since the beginning of 2016, raising alarm over the safety of activists and the status of the historic peace accords.

Paramilitary violence has been blamed for the spike as the armed groups look to strengthen positions in areas previously controlled by the FARC.